This invention relates to a pump adapted for mounting on a container, such as a jar or can, and operable to dispense small metered quantities of liquid from the container, the pump comprising a housing and a plunger in combination with a valve constituted by an annular washer mounted between the housing and the plunger and movable with the plunger, the washer being so related to the housing and plunger that it effects a good seal in the closed position and opens readily to permit passage of the liquid being pumped.
In valves for pressurized containers such as aerosol cans the gaskets are generally of the fixed type, having their outer portions firmly gripped between housing elements and their radially inner portions deformable to open and close an aperture, e.g., in a depressable stem, as in the patent to Abplanalp, U.S. Pat. No. 2,631,814. Kitabayashi U.S. Pat. No. 3,061,203 shows such a fixed gasket combined with a free gasket and operable to open a passage for paint and another passage for gas, both under pressure, for spray painting. British Pat. No. 1,112,531 shows a pump and valve assembly for a non-pressurized container wherein an annular "sealing ring" slides in an elongated recess, without deformation, between closed and open positions.
It is an object of the invention to provide a pump and valve assembly which is simple to manufacture and to operate, and which has a very efficient sealing arrangement to prevent leakage, both at rest and in use.
It is a further object of the invention to effect reliaable sealing by mounting an annular washer in a position to maiantain positive sealing contact with adjacent surfaces along a plurality of annular areas.
It is another object of the invention to provide an annular washer of rectangular cross-section, at rest, which is movable with the plunger and is adapted to be distorted, in operation, to a plurality of dished positions.
It is a further object of the invention to provide certain improvements in the form, construction and arrangement of the parts whereby the above-named and other objects may effectively be attained. The invention accordingly comprises an article of manufacture possessing the features, properties, and the relation of elements which are exemplified in the article hereinafter described, and the scope of the invention will be indicated in the claims.